Method of finishing metal fasteners



June 3, 1941.-

F. B. SMITHE ET AL METHOD OF FINISHING METAL FASTENERS Original FiledJan. 27, 1937 ATTORNEYS Patented June 3, 1941 ,F F 1 CE 2,244,223 METHODor FINISHING METAL FASTENERS Frank -B; Smithe, Douglaston, and AbrahamNovick, Flushing, N. Y., assignors to F. L. Smithe Machine 00., Inc.,New York, N. Y., a

corporation of New York Original application January 27,1937, Serial No.122,530. Divided and this application March 14, 1940, Serial No. 323,875

5 Claims. (CI. 51 281) This invention relates to the fabrication ofmetal fasteners, especially to fasteners of the type adapted to-beaffixed to a rear wall of an envelope below an apertured closure flap,and having tongues to be bent up into position to protrude through theaperture in the flap, and then to be bent back into retentive positionover the opposite margins of the aperture,

Ihe invention is more particularly concerned with the step of finishingthe fasteners while assembled in conventional stack formation as theyare sold to envelope manufacturers for application to the envelopes,this finishing step being effective to remove from the edges of thetongues the burr formed thereon in the course of die-cutting or stampingthe fasteners bodily from sheet metal.

While this burr may be of slight proportions and not of serious importapparently, it has been found to have sufficient abrasive effect uponthe fingers of an operative charged with the duty of bending up a largequantity of the tongues in the course of loading such envelopes, to Wearaway the cuticle uncomfortably and even dangerously in the course of asingle day.

Under such conditions, it is the general object of the present inventionto provide an effective method of reducing this objectionable burr to anextent which deprives it of its abrasive characteristic, and aparticular object is to accomplish this burr-reduction as a finishingoperation performed continuously upon a large number of the fastenerblanks assembled upon the conventional U-shaped wire holder disclosed inU. S. Letters Patent No. 1,827,901, and it may be the final step in thefabrication of the fasteners preparatory to furnishing each such salesunit to a user.

Another object of the invention is to provide means to facilitate thepresentation of the aforesaid stacks of fastener blanks for a bufiingoperation to reduce the iburrs effectively with a minimum of eifort andskill upon the part of an operative, and .at low cost for the operation;also with optimum accuracy, and without displacing any of the fastenerblanks from its relative order in the stack.

This application is a division of co-pending application Serial No.122,530, filed January 27, 1937 which has matured into Patent No.2,221,- 885 granted November 19, 1940.

Other objects and advantages of the invention will appear as thedescription of the particular physical embodiment selected forillustration and description progresses.

In the accompanying drawing, like characters of reference have beenapplied to corresponding parts throughout the several views which makeup the drawing, in which:

Fig. 1 is a view of a schematic character illustrating a boiling meansfor carrying into effect the method of the present invention;

Fig. 2 is a vertical sectional view taken on the line 55 of Fig. 1;

Fig. 3 is a view similar to Fig. 1 of another modification of the meansfor carrying the present invention into efiect; and

Fig. 4 is a vertical sectional elevation on the line l--'! of Fig. 3.

In one embodiment of means for carrying the present invention intoeffect, a couple of buffing wheels B2, B3 of suitable material arecaused to rotate about horizontal axes, these buffing wheels being inthe same vertical plane (see Fig. 2), which defines a path along which aconventional stack of fastener blanks, designated generally by thereference character S is fed lengthwise in the directionof the arrow i3.

Such a stack may desirably be of the form illustrated in U. S. LettersPatent 1,827,901, granted October 20, 1931, to which reference may behad for a more complete description than it is necessary to includeherein; and for the purposes of the present disclosure it will besufii'cient to point out the general contour and disposition of thefastener blank components it, which are assembled with their broad faces45 in contact to make up the stack.

Each fastener blank I4 is formed of thin metal, and as is evident froman inspection of the drawing, the blanks are cross-shaped so thatopposed re-entrant angles occur at the junctions of the body portions 2and 3 with the arms l and 5.

For the .purpose of maintaining a multiplicity of these blanks inorderly assembled relationship for shipment to envelope factories, andfor handling in such factories, provision is made of a staple-likemember Br having parallel legs 7 and v 8 thereof disposed in oppositere-entrant angles of the blank stack so as to embrace and interfit withthe blanks.

This staple-like holding member may be of considerable length, and thelegs 1 and 8 are bendable to a limited extent; extension beyond thestack Where provision is made of a holding plate 9 and a locking plateIii, both of which are impaled upon the said projecting portions tomaintain the stack against separation from, or

and :1: respectively; so that the invention pro-' vides for suchdisposition of the stacked blanks that the edges 4:1: and 5:0 arepresented in salient position for the action thereon of the buffing orfinishing wheels, as the stackof blanks is advanced past the finishingstation. 1

In the embodiment of means to carry the invention into effect, asillustrated in Figs. 1 and 2,

the presentation at the finishing stage F of the blanks l4, assembledupon a U-shaped staple or holder 6:0, as in the aforesaid arrangement ofPatent No. 1,827,901, is effected while the wire legs 1 and 8 of theholder retain the straight disposition in which they come from theoperation of assembling the blanks H1 in stack form on the staple, andin which straight disposition it is desirable to have them remain afterfinishing, for storage, transportation and use.

The method of treatment according to the modification illustrated inFigs. 1 and 2 provides for finishing treatment by the buffer wheels B2and B3 which are arranged in the same vertical plane as that occupied bythe tongues or arms 4 and 5, (see Fig. 2), of the blanks [4, as thestack S is advanced bodily from right to left. The leading end of thestack is supported by a guide 56.x and the bodily advancement of thestack is accomplished by means of a screw 34 rotatable in a head H bysuitable means, (not shown).

At the time of original assembly of the blanks in stack form upon thestaple 6.7:, or thereafter prior to the finishing step, the endretaining members 9 and H) are set in such a position as to leave spacefor a. certain amount of play of the blanks within the limits of thestack, and the effect is to afford room for each blank to be biasedindividually away from the contiguous succeeding blank in the directionof bodily feeding movement of the stack, from right to left in thepresent instance.

This starts with the first stack component, as Mr (see Fig, l), at thetime that the left-hand end of the stack passes into the finishingstation F and in order that only one blank it may be permitted to emergeinto finishing position at a time, spring friction devices N, N arepreferably provided, in conjunction with a pair of guides 33 iroughwhich the stack S is led for treatment.

The friction device includes a pair of spring fingers 3i and 32, eachfixed upon the troughlike guide member 33 mounted on a suitable support(not shown) and which serve as guides for the stack.

As the latter is advanced, by rotation of the screw 34 in the head H,one blank at a time is pressed forward through the fingers 3 l, 32 andreleased for the action of the buffing rolls, which cause it to springacross the gap shown, and its rugous edges E are thereby exposed forbufiing.

In another embodiment of the invention, illustrated in Figs. 3 and 4 ofthe drawing, a stack S", comprising a multiplicity of blanks l4assembled upon a staple or holder 66 substantially as disclosed in U. S.Letters Patent No. 1,827,901,1s presented for finishing at a station F",as by a pair of buffing wheels B t and l35,'the stack of blanks beingfed bodily past the station from right to left, by suitable mechanism,not shown.

The lower edges E of the closely assembled blanks l4 composing the stackrest upon a ledge or templet L and are caused to travel in successionover a shoulder C which is so disposed with relation to the bufiingwheel B4 that as the latter is rotated counter-clockwise against theexposed upper edges E of the blanks, (see Fig. 4), the wheel exerts adownward bias against the blanks which becomes effective to displacetransversely of the stack each successive blank when its lower edge isfed past the shoulder C. This displacement of each blank is permitted bythe nature of the support of the blanks on the staple 66, the elements Iand 8 allowing such displacement of individual blanks to the extentindicated by virtue of the slight looseness of the fasteners on thestaple, and as the displacement occurs, the leading edge E" of thecontiguous undisplaced blank is then exposed to the finishing action ofthe buffing which is effective to remove the residual burrs orrugosities left by the dies at the time of stamping out the blanks.

When the stack has been fed completely past the finishing station, andthe edges E and E" of all of the blanks have been thereby finished, thestack will be then replaced bodily at the starting point in reversedposition, top for bottom, and fed through again, for the purpose offinishing the edges E.

From the foregoing, it will be evident that in the operation of theseveral embodiments of means for carrying the invention into effect,there isinvolved, in each of these, the step of feeding bodily past afinishing station, as F in Figs. 1 and 2, or F" in Figs. 3 and 4, astack of blanks M assembled upon a staple or holder, as 6:0 or 68, sothat the bufing wheels or like finishing members as B2, B3 and B4, B5;in each instance, act upon one or more edges of the blanks M, as E, E,E", etc., to perform the step of removing therefrom the characteristicburrs or rugosities which remain after a die-cutting or stampingoperation.

While this removal of a burr from the edges of the fastening tongues orarms 4 and 5 of metal envelope fasteners is the intended use illustratedby way of example, it will be apparent that the invention is capable ofapplication in the continuous finishing, as by polishing or otherwisetreating of many different kinds of articles of which a multiplicity maybe assembled in stack form,

Furthermore, the several modes of presenting the articles individuallyfor treatment, while preserving-their relative order in their stacks, asby creating a gap in the stack, so that each blank is exposed completelyas in the form shown in Figs. 1 and 2; and the mode shown in Figs. 3 and4 according to which a relatively small sidewise displacemest of eachblank in turn exposes the edge, as E", of a contiguous blank fortreatmentyare merely illustrative physical embodiments of the idea ofmeans underlying the invention, and indicates the flexibility of thenovel method, which may be carried into effect by many othermodifications of the means illustrated, these not exhausting thepossible physical embodiments of such underlying idea of ments shown,but what we desire to cover by Letters Patent is set forth in theappended claims.

We claim:

1. The continuous method of finishing the raw edges of a multiplicity ofstamped sheet metal articles having identical contour and size, Whileassembled in stack form upon an elongated holder along which they arecapable of a limited adjustment; said method including the steps ofadvancing the stack of articles toward a finishing station, moving theend article of the stack with reference to the next adjacent articlewhile positioned at the finishing station so that a raw edge of thearticle to be finished is separated from the corresponding edge of thenext adjacent article and exposed, finishing such exposed raw edge andadvancing the stack of finished articles bodily away from the finishingstation.

2. The continuous method of removing burrs from the edges of amultiplicity of sheet metal articles having identical contour and size,while assembled in stack form upon an elongated holder along which theyare capable of a limited adjustment; said method including the step offeeding the stack of articles up to; a finishing station, the step ofsubjecting the edges of a plurality of contiguous articlessimultaneously to the action of a rotary bufiing tool adapted to exertthereon a bias tending to displace the articles as they successivelypass the station and the step of permitting said bias to becomeeffective to cause the end article of the stack to be displaced withreference to the next adjacent article to thereby expose the burred edgeof an article to the action of the buffing tool.

3. The method of finishing the raw edges of a plurality of thin sheetmetal articles having identical contour and size, which comprises thesteps of arranging the articles in a stack, applying a yielding pressureto the end article of the stack to urge said end article into contactwith the next adjacent article, displacing the end article of the stackso as to separate it from the next adjacent article by a free space andsubjecting a raw edge of the displaced article to the action of a rotaryfinishing instrument while maintaining the displaced article inalignment with the stack.

4. The method as set forth in claim 3 in which the displacement of theend article results from the pressure thereon of the rotary finishinginstrument.

5. The method of finishing the raw edges of a plurality of thin sheetmetal articles having identical contour and size, which comprises thesteps of arranging the articles in a stack, applying a yielding pressureto the end article of the stack to urge said end article into contactwith the next adjacent article, displacing the end article of the stackso as to separate it from the next adjacent article by a free space andsubjecting oppositely disposed raw edges of the displaced articlesimultaneously to the action of rotary finishing instruments Whilemaintaining the displaced article in alignment with the stack.

FRANK B. SMITHE. ABRAHAMI NOVICK.

